Air compressing system



June 12, 1934. H 11 HUNTER 1,963,020

AIR COMPRESSING SYSTEM Original Filed Nov. 3, 928 2 Sheets-Sheet 1 I IN VENTOR: 16 mi'flert Tjfzmiei;

WITNESSES.-

TTORNEYS.

June 12, 1934. H. T. HUNTER AIR COMPRESSING SYSTEM Original Filed Nov. 5, 1928 2 Sheets-Sheet 2 FIG. I

2 III:

GEE -l IN VEN TOR.- l erberi I'Jfimier,

Patented June 12, 1934 UNITED STATES AIR COMPRESSENG SYSTEM Herbert T. Hunter, Baltimore, Md., assignor to Doughnut Machine Corporation, New York, N. Y., a corporation of New York Original application November 3, 1928, Serial No.

317,078. Divided and this application September 30, 1931, Serial No. 566,066

2 Claims. (01. 137-78) This invention relates to air compressing systems intended for the generation and maintenance of a static head of air, as distinguished from systems designed for the production of compressed air in lar e quantities. A system of the specific type referred. to, although adaptable to other purposes is particularly useful with apparatus for cooking articles like doughnuts as instanced in U. S. Patent 1,492,542 granted to John C. Bergner, under date of April 29, 1924. In such apparatus, the static head of compressed air is relied upon to eiiect extrusion of plastic or dough through intermittently actuated die mechanism to form the raw articles which are to -be cooked. Obviously, the size of the extrusions under these conditions is'directly dependent upon the force behind the dough; but due to vacillaticns of a slow speed generating pump, considerable difficulty has been experienced heretofore in holding the compressed air head at a constant pressure with consequent lack of uniformity in the articles.

The present invention is a division from my co-pending application Serial Number 317,078,

filed November 3, 1928, which has matured into Patent No. 1,840,288, dated January 5, 1932, and is directed toward overcoming the recited drawbacks.

The noted desideratum I. attain through provision of a simple, efiicient and reliable distributing system capable ofready adjustment to-operate at any pressure predetermined upon,.and of accurately maintaining such pressure evenly and constantly, notwithstanding dwindling of the supply of material being acted upon.

In the drawings:

Fig. I is an illustration partly in side elevation and partly in vertical section of a doughnut machine equipped with the air distributing system of my invention.

Fig. II is a plan section of the machine taken as indicated by the arrows IIII in Fig. I; and,

Fig. III is a detail View mostly in section showing novel control means associated with my invention.

The doughnut machine herein illustrated for the piupcses of exemplifying one practical use of my improved air distributing system, is, generally speaking, of the type disclosed in the 90 United States patent hereinbefore referred to in that is comprises a circular receptacle for hot cooking liquor in which the articles to be cooked are slowly advanced afloat by an intermittently rotating cellular progressing means 11, and, after lapse of a predetermined period essential to proper cooking, ejected onto a discharge chute 12. The machine is driven by an electric motor 13 which is connected by a belt 14 to the high speed shaft I5 of a reduction gearing device comprehensively designated by the numeral 16. Through suitably interposed gear elements, shown in Fig. II, slow motion is communi'cated to the depending vertical shaft 17 of the progressing means 11 in rotating the latter intermittently for the purpose aforesaid. The machine further comprises a dough magazine 18 which is supported above the cooking receptacle l0 and, in the present instance, located exteriorly of the protective housing 19 of the machine. Under a static head of the compressed air, the raw dough is forced through an annular outlet of a die means 20 at the bottom of the magazine 18, said die means embodying a sleeve 21 which is intermittently operated to shear over a concentric disk 22 in severing successive extrusions: of the plastic or dough. Intermittent reciprocat-- ing motion is imparted to the sleeve 21 by a yoke lever 23 connected, through a rod-24, with an arm 25 in the machinery compartment beneath thereceptacle 10 within. the housing 19, for actuation by a cam 26 associated with the gearing device 16. In a doughnut. machine of the kind briefly outlined, I provide a pump such as shown at 30 in Figs. I and. II. The cylinder 31 of this pump is secured, for convenience, to the side of the casing of the speed reduction device 16: by bolts 32; and in this instance is disposedat an angle for the sake of economizingon headroom. within the bottomor machinery compartment' of" the housing 19. Within the cylinder 31 operates a piston whereof the rod 33 is guided in a removable top head 34. To the free end of the rod 33 is rigidly secured a yoke 35 with a transverse slot 36 to engage a crank roller 37 which is eccentrically mounted on a disk 38 at one end of the high speed shaft 15 of the gearing device 16. Under this arrangement, it will be seen that the pump 30 can be operated at high speeds without oscillatory movement of its cylinder 31 and without attendant vibration. The operation of the pump 30 is further eased and stabilized by virtue of a prolongation of the rod 33 beyond the lower end of the piston, said prolongation being guided in a tubular bearing 31a forming an axial extension of the cylinder 31. The pump 30 is of the single acting type, that is to say, compresses air only during the down stroke of the piston, relief being had incidental to the up stroke through radial ports not shown-at the top of the cylinder 31; while said pump is of the type and operative as fully set forth in my Patent No. 1,840,288, hereinbefore referred to. The substantially non-pulsating stream of compressed air generated by the pump as a consequence of operation at high speed, is conducted by a pipe 39 leading from a check Valve 40 to an equalizing tank 41 located in the machinery compartment beneath the receptacle 10.

In adapting my present improvements to a doughnut machine of the typified form, the compressed air from the equalizing tank 41 is conducted, through a pipe 42 to a fitting 43 secured to the roof of the machine, and from thence into the dough reservoir 18 through a flexible tube 44 connecting with a nipple 45 on the removable reservoir cover 46, which, as shown, is secured air tight by means of a yoke 47 with a clamp screw 48.

Referring now to Fig. III wherein the fitting 43 is illustrated in detail, it will be noted that the same has an elongated horizontal tubular body portion with one end turned up as at 49 for connection of the flexible tube 44, and bored transversely to afford a seat for a plug valv 50 with a manipulating handle 51. This valve 50 is kept open normally, and is provided as a means to shut-off the air flow during the intervals required in charging the dough receptacle 18. A vertical boss 52 at the opposite end of the fitting 43 is axially bored to take a needle valve 53 which has threaded engagement at 54 for the purpose of adjustment of its lower tapered end 55 in respect to the reduced portion 56 of the bore communicating direct into the hollow of the body of the fitting 43, to control bleeding of air through a lateral port 57 that discharges into the atmosphere. At the top, the needle valve stem carries a knurled adjusting ,head 58 which is cupped as shown to overhang the upper end of the boss 52.

By proper adjustment of the needle valve 53, it will be seen that any desired constant static pressure may be maintained in the system with pre-assurance of uniformity in the size of the extrusions released by the die mechanism 20 at the bottom jamb piece 61 which occupies a lateral opening of the boss 52, and which is urged inwards against the valve stem 53 by a thumb screw 62. This thumb screw 62 has threaded engagement in a block 63 fixedly attached to the corresponding side of the boss 52. The block 63 also afiords slide bearing for the stem 64 of a push valve 65 whereby the bleed port 57 can be held closed temporarily, through push of the thumb, until the pressure builds up in the system upon opening of the plug valve 50 after recharging the dough magazine 18. Upon being freed subsequently, the push valve 65 is automatically retracted to the normal position illustrated by a spring 66, thereby permitting escape of air through the bleed port 57.

From the foregoing it will be apparent that I have provided an organization capable of maintaining a static head of air under absolutely constant pressure, irrespective of gradual depletion of the dough supply within the magazine 18. It will moreover be seen that through careful regulation of the controlling needle valve 53, the pressure can be varied within fine limits to predetermine proportionately small variations in the size of the extrusions intermittently released by the die means 20.

Although I have herein shown and described my invention in connection with a commercial form of doughnut cooking apparatus, it can ob-' bleed port from the axial bore aforesaid may be temporarily closed.

2. A bleed device for air distributing systems comprising an elongated tubular fitting with an elbowed connection at one end, a normally open shut-off valve in said elbovved end, an angled axially bored extension at the other end of the tubular fitting having a lateral bleed port, an

adjustable needle valve co-active with a reduced portion of the axial bore, jamb means for securing the needle valve at the required adjustment, and a push valve whereby the bleed port may be temporarily closed.

' HERBERT T. HUNTER. 

